Electromagnetic properties of the human blood circulation

2018 ◽  
Vol 1 (2) ◽  
Keyword(s):  
Human Blood ◽  
Blood Circulation ◽  
Electromagnetic Properties

Togetherness amongPlasmodium falciparumgametocytes: interpretation through simulation and consequences for malaria transmission

Parasitology ◽  
2003 ◽  
Vol 127 (5) ◽  
pp. 427-435 ◽  
Author(s):  
F.-O. GAILLARD ◽  
C. BOUDIN ◽  
N. P. CHAU ◽  
V. ROBERT ◽  
G. PICHON
Keyword(s):  
Plasmodium Falciparum ◽  
Human Blood ◽  
Negative Binomial Distribution ◽  
Blood Circulation ◽  
Anopheles Arabiensis ◽  
Negative Binomial ◽  
Microscopic Level ◽  
Aggregation Process ◽  
Simulation Results ◽  
Density Dependency

Previous experimental gametocyte infections ofAnopheles arabiensison 3 volunteers naturally infected withPlasmodium falciparumwere conducted in Senegal. They showed that gametocyte counts in the mosquitoes are, like macroparasite intakes, heterogeneous (overdispersed). They followed a negative binomial distribution, the overdispersion coefficient seeming constant (k=3·1). To try to explain this heterogeneity, we used an individual-based model (IBM), simulating the behaviour of gametocytes in the human blood circulation and their ingestion by mosquitoes. The hypothesis was that there exists a clustering of the gametocytes in the capillaries. From a series of simulations, in the case of clustering the following results were obtained: (i) the distribution of the gametocytes ingested by the mosquitoes followed a negative binomial, (ii) thekcoefficient significantly increased with the density of circulating gametocytes. To validate this model result, 2 more experiments were conducted in Cameroon. Pooled experiments showed a distinct density dependency of thek-values. The simulation results and the experimental results were thus in agreement and suggested that an aggregation process at the microscopic level might produce the density-dependent overdispersion at the macroscopic level. Simulations also suggested that the clustering of gametocytes might facilitate fertilization of gametes.

scholarly journals Closed-Loop Multiscale Computational Model of Human Blood Circulation. Applications to Ballistocardiography

2021 ◽  
Vol 12 ◽  
Author(s):  
Jeremy Rabineau ◽  
Antoine Nonclercq ◽  
Tim Leiner ◽  
Philippe van de Borne ◽  
Pierre-Francois Migeotte ◽  
...  
Keyword(s):  
Computational Model ◽  
Human Blood ◽  
Blood Circulation ◽  
Closed Loop ◽  
Scaling Law ◽  
The Body ◽  
Whole Body ◽  
Mechanical Activity ◽  
Clinical Records ◽  
The Impact

Cardiac mechanical activity leads to periodic changes in the distribution of blood throughout the body, which causes micro-oscillations of the body’s center of mass and can be measured by ballistocardiography (BCG). However, many of the BCG findings are based on parameters whose origins are poorly understood. Here, we generate simulated multidimensional BCG signals based on a more exhaustive and accurate computational model of blood circulation than previous attempts. This model consists in a closed loop 0D-1D multiscale representation of the human blood circulation. The 0D elements include the cardiac chambers, cardiac valves, arterioles, capillaries, venules, and veins, while the 1D elements include 55 systemic and 57 pulmonary arteries. The simulated multidimensional BCG signal is computed based on the distribution of blood in the different compartments and their anatomical position given by whole-body magnetic resonance angiography on a healthy young subject. We use this model to analyze the elements affecting the BCG signal on its different axes, allowing a better interpretation of clinical records. We also evaluate the impact of filtering and healthy aging on the BCG signal. The results offer a better view of the physiological meaning of BCG, as compared to previous models considering mainly the contribution of the aorta and focusing on longitudinal acceleration BCG. The shape of experimental BCG signals can be reproduced, and their amplitudes are in the range of experimental records. The contributions of the cardiac chambers and the pulmonary circulation are non-negligible, especially on the lateral and transversal components of the velocity BCG signal. The shapes and amplitudes of the BCG waveforms are changing with age, and we propose a scaling law to estimate the pulse wave velocity based on the time intervals between the peaks of the acceleration BCG signal. We also suggest new formulas to estimate the stroke volume and its changes based on the BCG signal expressed in terms of acceleration and kinetic energy.

scholarly journals Influence of the metallized coils on human leg blood circulation

2021 ◽  
Author(s):  
Jurijs Dehtjars ◽  
Ksenija Jasina ◽  
Viesturs Larins ◽  
Aleksandrs Okss ◽  
Konstantins Pudovskis ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Blood Flow ◽  
Human Body ◽  
Human Blood ◽  
Blood Circulation ◽  
Alternating Magnetic Field

The aim of the study was to find out if magnetic field generated by the human body affects a human blood flow. The idea is based on Lenz's law where the blood flow induces an opposing alternating magnetic field (OAMF). In the experiment the OAMF will be modulated by repeating heart contractions (pulses). In an experiment with metallized coils it was found that wearing metal coils affects blood flow and it differs from when coils were not worn.

Some Observations on the Viscosity of Pathological Human Blood Plasma

1965 ◽  
Vol 13 (02) ◽  
pp. 492-499 ◽  
Author(s):  
L Dintenfass
Keyword(s):  
Blood Plasma ◽  
Human Blood ◽  
Blood Circulation ◽  
Flow Characteristics ◽  
Human Blood Plasma ◽  
Correct Evaluation ◽  
Great Range ◽  
Erythrocyte Sedimentation

SummaryViscosities of blood plasma obtained from patients suffering from leukaemia, macroglobulinaemia, polycythaemia, spherocytosis, haemophilia and myelofibrosis has been studied by means of a rotational cone-in-cone viscometer. The data obtained is not intended to characterize the specific diseases. The aim is to show that a great range of viscosities may be found in various samples of human blood plasma and that the pathological plasma may show non-Newtonian and thixotropic flow characteristics.It is suggested that determination of plasma viscosities, over a range of rates of shear, might contribute to our understanding of some problems of blood circulation and might be beneficial in more correct evaluation of the erythrocyte sedimentation tests.

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